diff --git a/dm_std_lib/std/core/string.dm b/dm_std_lib/std/core/string.dm
index 6344807..c00552d 100644
--- a/dm_std_lib/std/core/string.dm
+++ b/dm_std_lib/std/core/string.dm
@@ -1,5 +1,8 @@
 ns std::core
 
-pub int String
+pub int String {
+    bytes: Array<Byte>
+}
 
-impl StringImpl(fld bytes: Array<Byte>) : String
+#[internal]
+impl StringImpl(bytes) : String
diff --git a/sketching/curl.dms b/sketching/curl.dms
index 1b0519b..2ff17b8 100644
--- a/sketching/curl.dms
+++ b/sketching/curl.dms
@@ -13,3 +13,68 @@ fn main = jsonClient()
     map || ( it.body.accessToken )
     fold println
     ()
+
+# Better: main which returns IO (a Callable?) automatically calls the IO
+# Also, JsonClient can "login" using various methods, such as a Bearer token
+
+use std::http::{jsonClient, bearerToken}
+
+fn main = jsonClient(
+    baseUrl: 'http:/localhost:1234',
+    auth: bearerToken || ( post('/login', username: 'test', password: 'test') map || ( it.body.accessToken ) )
+)
+    get '/greeting'
+    map || ( it.body.greeting )
+    fold println
+
+pub int HttpReqOpts {
+    headers: Map<String, Any>
+}
+
+pub int GetOpts : HttpReqOpts
+
+pub int HttpClient {
+    baseUrl: String
+    fn get(path: String, opts?: GetOpts): IOEither<HttpRequestError, HttpResponse>
+    fn post(path: String, body: Any, opts: PostOpts): IOEither<HttpRequestError, HttpResponse>
+}
+
+pub int JsonClient : HttpClient
+
+pub int JsonClientOpts {
+    baseUrl: String
+    fn getAuth(#[self] client: JsonClient) -> HttpClientAuth
+}
+
+pub int HttpClientAuth = (reqBuilder: HttpRequest::Builder) -> Void
+
+impl : JsonClient {
+    baseUrl: String
+    fld auth: HttpClientAuth
+
+    ctor (opts: JsonClientOpts) {
+        self.baseUrl = opts.baseUrl
+        self.auth = opts.getAuth(self)
+    }
+
+    impl fn get(path, opts) = IOEither::of || (
+         HttpRequest::builder() tap || {
+            url = baseUrl + path
+            method = 'GET'
+            headers = opts?.headers ?: [:]
+            cookies = opts?.cookies ?: [:]
+            auth(self)
+        }()
+    )
+}
+
+pub fn jsonClient(opts: JsonClientOpts): JsonClient = JsonClientImpl(opts)
+
+pub fn bearerToken(tokenGetter: (#[self] client: JsonClient) -> IOEither<HttpRequestError, String>) {
+    |client: JsonClient| {
+        let token = tokenGetter.hydrate(self: client)().unwrap()
+        |reqBuilder: HttpRequest::Builder| {
+            reqBuilder.headers['Authorization'] = "Bearer $token"
+        }
+    }
+}
\ No newline at end of file